Atomic Radius Trends: Variation of Atomic Radius in a Period and Down The Group
Atomic radius trend explains how the size of atoms changes across a period and down a group in the periodic table. As we move from left to right across a period, atomic radius generally decreases due to an increase in effective nuclear charge, which pulls electrons closer to the nucleus. On the other hand, as we move down a group, atomic radius increases because new electron shells are added, increasing the distance between the nucleus and outermost electrons. Understanding this variation is essential for explaining periodic properties and chemical behavior of elements.